PDBsum entry 5csg

Immune system

PDB id: 5csg

Contents

Protein chain

100 a.a.

Ligands

ACT

Waters ×105

PDB id:

5csg

Name:

Immune system

Title:

The crystal structure of beta2-microglobulin r97q mutant

Structure:

Beta-2-microglobulin. Chain: a. Fragment: unp residues 21-119. Engineered: yes. Mutation: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: b2m, cdabp0092, hdcma22p. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.50Å R-factor: 0.182 R-free: 0.225

Authors:

M.De Rosa,M.Bolognesi,S.Ricagno

Key ref:

T.Le Marchand et al. (2018). Conformational dynamics in crystals reveal the molecular bases for D76N beta-2 microglobulin aggregation propensity. Nat Commun, 9, 1658. PubMed id: 29695721

Date:

23-Jul-15 Release date: 10-Aug-16

Protein chain

P61769  (B2MG_HUMAN) -  Beta-2-microglobulin from Homo sapiens

Seq: 119 a.a.

Struc: 100 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Nat Commun 9:1658 (2018)

PubMed id: 29695721

Conformational dynamics in crystals reveal the molecular bases for D76N beta-2 microglobulin aggregation propensity.

T.Le Marchand, M.de Rosa, N.Salvi, B.M.Sala, L.B.Andreas, E.Barbet-Massin, P.Sormanni, A.Barbiroli, R.Porcari, C.Sousa Mota, D.de Sanctis, M.Bolognesi, L.Emsley, V.Bellotti, M.Blackledge, C.Camilloni, G.Pintacuda, S.Ricagno.

ABSTRACT

Spontaneous aggregation of folded and soluble native proteins in vivo is still a poorly understood process. A prototypic example is the D76N mutant of beta-2 microglobulin (β2m) that displays an aggressive aggregation propensity. Here we investigate the dynamics of β2m by X-ray crystallography, solid-state NMR, and molecular dynamics simulations to unveil the effects of the D76N mutation. Taken together, our data highlight the presence of minor disordered substates in crystalline β2m. The destabilization of the outer strands of D76N β2m accounts for the increased aggregation propensity. Furthermore, the computational modeling reveals a network of interactions with residue D76 as a keystone: this model allows predicting the stability of several point mutants. Overall, our study shows how the study of intrinsic dynamics in crystallo can provide crucial answers on protein stability and aggregation propensity. The comprehensive approach here presented may well be suited for the study of other folded amyloidogenic proteins.